Optical disk reproducing apparatuses such as compact disk players have come into wide use in recent years.
Generally, recorded on the optical disk are the recorded information, such as music, and the index information, such as the playing time in connection with the recorded information.
In an optical disk reproducing apparatus, it has been a practice to utilize the index information, such as the playing time, to edit information such as music on a magnetic tape by combining an arbitrary program reproduction and a tape recorder.
Conventionally, an optical disk player of this type has a constitution as shown in FIG. 9 through FIG. 11.
That is, FIGS. 9 and 10, number 1 denotes a signal detecting unit comprising a light pickup device or the like which reads out music information or playing time information recorded on an optical disk (hereafter simply called a disk), numeral 2 denotes a signal output unit which processes information read by the signal detecting unit, converts it into an audio signal and output the thus obtained audio signal, number 3 denotes a control unit which controls the signal detecting unit 1 and the signal output unit 2, numeral 4 denotes a display unit which displays by means of the control unit 3 the playing time read by the signal detecting unit 1 and information inputted from a key switch unit, and numeral 5 denotes a key switch unit comprising a play key 5a which commands the control unit 3 to start playing and a continuous playing time specifying key 5b which specifies a time to continue a play to the control unit 3.
An arbitrary time can be specified to the control unit 3 by using the number keys (0 to 9) 5c and the foregoing continuous playing time specifying key 5b.
Further, a control as shown in the flowchart of FIG. 11 is accomplished in accordance with the above constitution.
In other words, whether the play key 5a has been depressed is determined in step 1, and if it has been depressed, then the control proceeds to step 4, and if it has not been depressed, then the control proceeds to step 2. In step 2, whether the continuous playing time has been specified is determined, and if it has not been specified, the control returns to step 1. In step 3, the specified continuous playing time is displayed in numerical characters on the display unit 4 by means of the control unit 3. In step 4, music information or the like recorded on a disk is played by the signal detecting unit 1 and the signal output unit 2. In step 5, the signal detecting unit 1 reads out the playing time information from the disk, compares the read playing information with the continuous playing time specified in step 2 to determine whether play has ended, and if it has ended, returns to step 1, and if it has not ended, steps 4 and 5 are repeated. In case the continuous playing time is not specified, the signal detecting unit 1 determines that the play is ended according to the ended play information of the disk.
However, because the display is only given by numeric characters when a continuous playing time is specified according to the conventional constitution described above, reading errors often caused errors in specifying the continuous playing time when a quick operation was made.
Conventionally, one of the optical disk players of the above type employed a constitution as shown in FIG. 12 through FIG. 15.
As shown in FIGS. 12 and 14, numeral 1 denotes a signal detecting unit comprising a light pickup device which reads out music information and play time information recorded on an optical disk (hereafter simply called a disk), numeral 2 denotes a signal output unit which processes the information read by the signal detecting unit, converts it into audio signal and outputs the audio signal, 13 denotes a control unit which controls these signal detecting unit 1 and the signal output unit 2 and contains in a part thereof a control unit for added and subtracted time display 16. 14 denotes a display unit which displays by means of the control unit 13 the playing time read by the signal detecting unit 1 and information input from the key switch unit 15 which comprises a play key 15a which commands the control unit 13 to start playing, reproduction time input key 15b which specifies the control unit 13 with a time to cause to continue the play, a music input key 15c which causes the storage of music to be played, and the number key 15d.
The continuous playing time is specified to the control unit 13 by using the number key 15d and the reproduction time input key 15b. Any music to be played is specified to the control unit 13 by using the number key 15d and the music input key 15c.
As shown in FIG. 13, the control unit 16 for added and subtracted time display comprises a specified reproduction time storage unit 18 which stores the reproduction time specified by the reproduction time input means 17, a reproduced music storage unit 20 which stores the music specified by a stored music input means 19, a stored music reproduction time adding unit 21 which obtains the sum of the stored music and the reproduction time, a subtracting means 22 which subtracts the sum of the stored music reproduction time from the specified reproduction time, and a time display means 23 which displays in numeric characters the data obtained by the subtracting means 22.
A control as shown in the flowchart of FIG. 15 is effected by the constitution described above.
That is to say, step 1 determines whether the play key 15a is depressed, and if depressed, the control proceeds to step 10, and if not pressed, the control proceeds to step. 2. In step 2, the presence of the input of reproduction time Tp is determined, and if no input is present, the control shifts to the step 3, and if input is present, the control shifts to the step 4. The initial value of the reproduction time Tp during this shift is 0. In step 3, in order to determine whether the step has gone to the step 4 even once, whether Tp is equal to 0 is determined, and if equal to 0, the control returns to step 1, and if not equal to 0 the control shifts to step 4. In step 4, the presence of an input to store the played music is determined, and if no input exists, the control shifts to the step 5, and if an input exists, the control shifts to step 6. In step 5, the presence of the music stored for reproduction is determined, and if it is present, control shifts to the step 8, and if it is not present, the control returns to step 1. In step 6, in order to obtain the sum Tm of the stored music reproduction time, the reproduction time is added to Tm in the stored music reproduction time adding unit each time the stored music is inputted therein, and the control shifts to step 7. In step 7, the sum Tm of the stored music reproduction time is subtracted from the specified reproduction time by the subtracting means 12. In step 8, whether the remaining time Ts is smaller than 0 is determined, and if not smaller than 0, the control shifts to step 9, and if smaller than 0, the control returns to step 12. In step 9, the remaining time is displayed in the display unit by the time display means 13 and the control returns to step 1. In step 12, negative numbers are displayed in the display unit by the number displaying means 13 to indicate the insufficient time and to inform that it is impossible to completely reproduce all of the stored musics within a specified reproduction time, and the control returns to step 1. In step 10, the music information or the like which is recorded on a disk by the signal detecting unit 1 and the signal output unit 2 is played. In step 11, the signal detecting unit 1 reads out the playing time information from the disk, compares the playing time with the specified reproduction time specified in the step 2 to determine whether the play has ended, and if the play has ended, control returns to the step 1, and if the play has not ended, then steps 10 and 11 are repeated. In case the continuous playing time is not specified, the play is determined to have ended according to the ended play information of the disk.
However, in such a conventional constitution as above, a first problem encountered is that only the remaining time is displayed and the operator cannot recognize unless the operator calculates the total reproduction time required using the head. A second problem encountered is that an error in recognition is likely to occur even if the stored music reproduction time exceeded the specified reproduction time because the display is given only in negative numbers.